Traffic jams without bottlenecks—experimental evidence for the physical mechanism of the formation of a jam

By Y. Sugiyama, M. Fukui, M. Kikuchi, K. Hasebe, A. Nakayama, K. Nishinari, S. Tadaki, S. Yukawa. 2008

769 citations recorded by the source corpus.

A traffic jam on a highway is a very familiar phenomenon. From the physical viewpoint, the system of vehicular flow is a non-equilibrium system of interacting particles (vehicles). The collective effect of the many-particle system induces the instability of a free flow state caused by the enhancement of fluctuations, and the transition to a jamming state occurs spontaneously if the average vehicle density exceeds a certain critical value. Thus, a bottleneck is only a trigger and not the essential origin of a traffic jam. In this paper, we present the first experimental evidence that the emergence of a traffic jam is a collective phenomenon like ‘dynamical’ phase transitions and pattern formation in a non-equilibrium system. We have performed an experiment on a circuit to show the emergence of a jam with no bottleneck. In the initial condition, all the vehicles are moving, homogeneously distributed on the circular road, with the same velocity. The average density of the vehicles is prepared for the onset of the instability. Even a tiny fluctuation grows larger and then the homogeneous movement cannot be maintained. Finally, a jam cluster appears and propagates backward like a solitary wave with the same speed as that of a jam cluster on a highway.

Subfields: Control and Systems Engineering, Ocean Engineering, Transportation

View Paper: https://www.semanticscholar.org/paper/50751265856cdaeb0b755947f23b85f1c7b55f4c

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Citations in the corpus

Flow: Architecture and Benchmarking for Reinforcement Learning in Traffic Control (2017, methodology): “…of controllers which optimize the system-level velocity or fuel consumption, in the presence of different types of vehicles, model noise, etc. Single-lane Ring Roads: The ring road network consists of a circular lane with a speciﬁed length, inspired by the 230m track studied by Sugiyama et al. [5].”
String-Stable CACC Design and Experimental Validation: A Frequency-Domain Approach (2010, background): “No accident or bottleneck needs to be present, and only too much traffic or erratic driving behavior may cause a shockwave of continuously increased braking upstream a string of vehicles, until vehicles come to a halt, and a traffic jam results [7].”
Flow: A Modular Learning Framework for Mixed Autonomy Traffic (2017, methodology): “For example, in the context of trafﬁc networks, evaluating with respect to the known human performance is restrictive; it is well known that human driving behavior induces (suboptimal) stop-and-go trafﬁc in a wide regime of trafﬁc scenarios [14], [15].”
Saving Human Lives: What Complexity Science and Information Systems can Contribute (2014, neutral): “In trafﬁc ﬂows, for example, researchers have found that “phantom” trafﬁc jams can occur in the absence of accidents or bottlenecks [16,17].”
Energy saving potentials of connected and automated vehicles (2018, background): “Smoother velocity transitions of the host vehicles are expected to positively influence the motion of upstream traffic, reduce the chance of a phantom jam, caused by small disturbance, [89], [90], [91] and lower fuel used by the entire queue of vehicles as experimentally shown in [92].”